body{margin:0;font-family:system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif;background:#f3f4f6}.app{min-height:100vh;display:flex;justify-content:center;align-items:center;padding:16px}.chat-container{width:100%;max-width:520px;height:80vh;background:#ffffff;border-radius:16px;box-shadow:0 10px 30px #0f172a1f;display:flex;flex-direction:column;overflow:hidden}.chat-header{padding:12px 16px;border-bottom:1px solid #e5e7eb;background:linear-gradient(90deg,#0ea5e9,#22c55e);color:#fff}.chat-header h1{margin:0;font-size:18px}.chat-header p{margin:2px 0 0;font-size:13px;opacity:.9}.messages-area{flex:1;padding:12px 16px 8px;overflow-y:auto;background:#f9fafb}.loading,.empty-state{text-align:center;margin-top:24px;color:#6b7280;font-size:14px}.message{display:flex;flex-direction:column;margin-bottom:8px;max-width:75%}.message.from-me{margin-left:auto;align-items:flex-end}.message.from-other{margin-right:auto;align-items:flex-start}.message-content{padding:8px 10px;border-radius:16px;font-size:14px;line-height:1.4}.message.from-me .message-content{background:#0ea5e9;color:#fff;border-bottom-right-radius:4px}.message.from-other .message-content{background:#e5e7eb;color:#111827;border-bottom-left-radius:4px}.message-time{font-size:11px;color:#6b7280;margin-top:2px}.input-form{display:flex;gap:8px;padding:10px 12px;border-top:1px solid #e5e7eb;background:#ffffff}.message-input{flex:1;border-radius:999px;border:1px solid #d1d5db;padding:8px 12px;font-size:14px;outline:none}.message-input:focus{border-color:#0ea5e9;box-shadow:0 0 0 1px #0ea5e94d}.send-btn{border:none;border-radius:999px;padding:8px 16px;background:#0ea5e9;color:#fff;font-size:14px;font-weight:500;cursor:pointer;transition:background .15s ease}.send-btn:hover{background:#0284c7}.send-btn:disabled{opacity:.6;cursor:default}